In order to obtain the internal frost heaving force development characteristics and change rule of frozen wall in the process of the formation and melting in cretaceous stratum, and then take analysis of mechanics features and safety evaluation of frozen wall, in a mine of Inner Mongolia, the field measurement research of internal and external frost heaving force and pore water pressure in the freeze-thaw process of frozen wall has been carried out. The measured results show that it formed uneven frost heaving stress in internal and external of frozen wall in freeze-thaw process, in the test the maximum of freezing pressure reach to 6.0MPa, it is 2.4 times of initial pressure in the layer; When the shaft excavated to test layer the freezing pressure reduced linearly, then the freezing pressure rebounded slightly when the wall was pouring, and finally the frost heaving force reduced to 0 when frozen wall melt, back to the pressure effected by soil and water.